Bulkhead-door arrangement



Aug. 20, 1929. T. v. MCDONALD 1,725,094

BULKHEAD DOOR ARRANGEMENT Filed Oct. 15, 1926 2 Sheets-Sheet l 3 Jiy. I l 3 INVENTOR.

TZeoIo Q V/fiDamZd T. v. MCDONALD 1,725,094

BULKHEAD DOOR ARRANGEMENT Filed Oct. 15, 1926 2 Sheets-Sheet 2 Aug. 20, 1929.

A TTORNEY.

R a I m m 1 .J 0 V A w d a 4 m 1 0 o a o o H o o 0 a M W i 2 e ||l||||||wi|1|1|||||| 1] I I? x 470 mm M H m 4 a 1 hm u u 2 u n 4 u w u 1 m 5 HI, H 3 2,4. x 1 Wm M o '1 o n a 2 u n a n 2 m f u n n. J m I 1 1||||I| I IL M l Patented Aug. 20, 1929.

UNITED STATES THEODORE V. MCDONALD, F DETROIT, MICHIGAN.

BULKHEAD-DOOR ARRANGEMENT.

Application filed October 15, 1926. Serial Io. 141,736.

This invention relates to improvements in bulkhead door arrangements and is primarily intended for use in underground shafts.

W'hen tunnelling along a shaft it is customary to provide excess air pressure in that portion of the shaft in which work is being done to lessen the possibility of the sides and roof of the shaft falling in before they have been shored up. In order to accomplish this bulkhead doors are employed to shut off that portion of the shaft into which excess air pressure has been forced so as to hold the pressure therein. Moreover it is usual to F provide an intermediate air chamber so that the excess air pressure may be equalized in the two shaft portions to facilitate the opening of the door between them.

This invention aims, among other things, to provide a bulkhead door arrangement wherein a door is pivotally mounted on its frame in such a manner that, as soon as the air pressure on both sides of the door has been equalized, it may be opened or closed far more quickly and with far less effort than doors held in position by means of clamps which are frequently employed for this purpose. Again my doors are materially lighter and cheaper to manufacture than the clamped-on type of door.

Another object of the invention is to provide a bulkhead door arrangement wherein the door is pivotally mounted on its frame in such a manner that the door is self aligning and will tend to make a joint evenly all around the frame against which it is forced as soon as air pressure is increased within that portion of the shaft in which the door is being used.

The invention, which consists in certain novel construction and combination of parts, is hereinafter more fully described with the aid of the accompanying drawings, in which:

Figure 1 illustrates the method in which the invention is applied.

Figure 2 is an elevation of a doorand doorframe,

Figures 3 and 4 are sections on the lines IIIIII and IVIV of Figure 2, and

Figure 5 is a partial perspective view of a door and doorframe showing the mounting arrangement of the former.

Referring to the drawings, 1 designates a tunnel shaft having its roof and sides shored up in the ordinary manner as shown at 2.

Built into the shoring are arches 3, usually made of concrete, which support thedoorframes 4. The latter support the bulkhead doors 5, in a manner hereinafter described, which divide the shaft into sections such as the tunnel portion 6 in which tunnelling is in progress, the intermediate air chamber 7 and the completed portion of the shaft 8.

I will now proceed to describe in detail one door and doorframe and the mounting means for the former.

Secured to the doorframe 4 are angle brackets 9 arranged in pairs one above the other and having a hinge pin 10 between each pair. On one side of' the door 5 are similar angled brackets 11 and 11 also arranged in pairs one above the other. The outer angle brackets 11 support hinge pins 12, and the intermediate angle brackets 11 have bolts or stops 13 passing through them and arranged substantially parallel with the surface of the door.

Hinge members 14 having eyes 15 and 15 at their ends are mounted on the hinge pins 10 and 12, so that the hinge members are free to swing about the pins 10 and the door is free to swing about the hinge members on the pins 12.

Intermediately of their length the hinge members 14 rest between the upper and lower angle brackets 11 which form guides so that the pivotal movement of the door on the pins 12 is limited in one direction by the surface of the door or in the other direction by the stops 13 which come in contact with the hinge members when the door has been turned in one direction or the other to a predetermined angle.

It will be noted that the door itself is preferably made of sheet metal, and in order to brace it against buckling from air pressure exerted against it re-inforcing members such as the I-beam 16 are usually welded or otherwise secured thereon transversely. In the door, usually towards its upper end, a window 17 may be provided. This window is generally held in place by means of a frame 18 secured to the door as by bolts 19.

Around the margins of the door, on the opposite side to the angle brackets 11 and 11*, a resilient pad 20 is secured as by strips 22. The latter are fastened in position as by bolts 21 which pass both through the strips and the door. This pad is arranged in such a manner that it will bear all around against the sides of the doorframe when the door is in closed position. It is preferable to make this pad of a comparatively soft rubber or composition so that it will compress to a marked extent when pressure is exerted against the door, so that it will compensate for any slight irregularities in the surface of the door or doorframe and make a tight joint between them.

From the foregoing it will be clearly seen that the bulkhead door arrangement is so constructed that 'air pressure exerted against the door will tend to force the latter against its frame as the door is self-aligning. Moreover the construction of the door itself and its supporting means is such that a much lighter and cheaper type of door may be em ployed, moreover the door is capable of being opened or closed with much greater rapidity and case than is the case with a door bolted onto its frame.

Having thus described the invention what I-claim as my invention and desire to secure by Letters Patent is:

In an arrangement of the character described, the combination of a door frame and a door, angle brackets on said doorframe having outwardly projecting flanges at their adjacent ends with opposed openings therethrough, a hinge pin extending through said openings a hinge member through which one end of said hinge pin passes, and a plurality of angle brackets arranged in pairs on said door each pair having flanges extending outwardly at their adjacent ends and being in alignment with said first named pair of angle brackets when the door is 'mounted in position, the flanges of the angle brackets on the door having opposed apertures therethrough, a hinge pin extending through the apertures in the pair of angle brackets furthest from the brackets on said door frame, the other end of the hinge memher being pivotally mounted on said latter hinge pin, and each pair of intermediate angle brackets having a stop supported by their opposed apertures against one of which the outer side of the hinge member comes to rest when the door is swung pivotally in one direction or the other with respect to the hinge member.

THEODORE V. MOD ONALD. 

